I took the Ballast PDD practice exam, and there is one question I still feel like I don't entirely understand. It shows an electrical diagram and asks 'What is the voltage of the service obtained at each tap?"
The diagram it shows is a 3 phase, 4 wire system. But everything I am reading says that 277/480 looks pretty much the same as 120/208, both are 3 phase 4 wire, and I can't find a diagram that specifically shows 277/480.
How would a 277/480 system look different from a 120/208 system?
Please sign in to leave a comment.